Inking arrangement in offset proof press for multicolor printing

ABSTRACT

An inking arrangement in an offset proof press for multicolor printing comprising a stationary inking unit and a carriage inking unit having plural groups of rollers, respectively, each roller group representing a particular color. Control means are provided for selectively matching one roller group in the carriage inking unit with a predetermined roller group in the stationary inking unit, allowing a single proof press to print successively with two or more color inks by the cooperative control of these two inking units.

United States Patent 1191 Oda 111 3,734fii4 1 51 May 22, 1973 INKING ARRANGEMENT IN OFFSET PROOF PRESS FOR MULTICOLOR PRINTING Inventor: Osamu Oda, Kyoto, Japan Assignee: Dainippon Screen Seizo Kabushiki Kaisha, Horikawa-dori, Kamigyokn, Kyoto, Japan Filed: Apr. 8, 1971 App1.No.: 132,412

Foreign Application Priority Data Aug. 20, 1970 Japan ..45 72343 US. Cl. ..l01/186, 101/205,101/252, 101/354 Int. Cl. ..B41f 3/28, B4lf 3/42 Field of Search ..101/146, 186, 187, 101/188-192, 205-208, 252, 256, 260, 269, 354, 355

[56] References Cited UNITED STATES PATENTS 1,100,409 6/1914 Vandercook ..101/252 1,898,605 2/1933 Vandercook et al ..10l/355 2,610,581 9/1952 Vandercook et al ..101/208 FOREIGN PATENTS OR APPLICATIONS 975,162 3/1951 France ..l0l/252 Primary ExaminerJ. Reed Fisher Attorney-Spensley, Horn & Lubitz [57] ABSTRACT An inking arrangement in an offset proof press for multicolor printing comprising a stationary inking unit and a carriage inking unit having plural groups of rollers, respectively, each roller group representing a particular color. Control means are provided for selectively matching one roller group in the carriage inking unit with a predetermined roller group in the stationary inking unit, allowing a single proof press to print successively with two or more color inks by the cooperative control of these two inking units.

8 Claims, 4 Drawing Figures PATENTED W32 3,734,014

G F E VII/4mm FIG. I A

FIG. 3

I NVEN TOR.

INKING ARRANGEMENT IN OFFSET PROOF PRESS FOR MULTICOLOR PRINTING This invention relates to an inking arrangement in an offset proof press for multicolor printing.

Generally in multicolor printing, a color reproduction is obtained by first separating the color image of the original into several color components, e. g., yellow, magenta, cyan and a neutral color, for preparing the respective color printers, and secondly by overprinting on a white paper with these printers with the respective color inks. For testing the printing efficiency of offset plates for multicolor printing, a proof work is performed according to a conventional mode known per se: First, a required amount of ink of the first color, for instance, yellow ink is fed to the inking unit of the proof press, while clamping the yellow printer onto the form bed on the press and gripping a sheet of paper onto the printing bed on the press, and then the proof press is operated to print a yellow color image. Thereafter, the inking unit is washed for completely removing the yellow ink therefrom. Nextly, a second color ink, e.g., magenta ink is fed to the inking unit, followed by the change of printer into the magenta plate for printing the magenta image over the yellow image. The same processes are repeated for successively overprinting the cyan and black images so that the color image of the original will be reproduced by the combination of four color inks. In such a conventional proof press work, it will be obviously necessary to repeat the operations of the feeding and washing of inks as many times as the number of colors used for the color reproduction. Such repeated operations as well as the necessity of change in color inks will be troublesome. It is practically impossible to start the printing operation immediately after the feed of new ink. Usually it takes, before initiating the printing operation, much time and labor for adjusting the viscosity of ink used and the amount of ink on the ink rollers.

In the case where an ordinary printing operation runs on an offset press for producing a great number of printed copies, the time and labor required for the exchange of inks and other adjusting works will offer no serious problem, since such time and labor occupy only a small portion of the entire work involved. In the case of proof press work, however, the number of copies printed per one plate will be ten at most. Particularly in the case of multicolor proof printing, a major portion of the working time is spent for the exchange of ink, resulting in lowering the working efficiency. Further, in order to prevent unevenness of ink distribution, a much greater amountof ink is needed than that of actually required for printing per se, resulting in increasing loss of ink. Thus, the need for an improved inking arrangement is evident.

According to another mode of proof press work, a plurality of proof presses is used for testing a number of offset plates, wherein each proof press is exclusively used for a particular color. Therefore, at least four proof presses are needed for testing four-color printing. However such a proof press work which uses a plurality of proof presses, increases the cost of equipment and requires a great deal of floor space and labor.

The present invention aims, therefore, to eliminate the disadvantages referred to above. According to the invention, an improved inking arrangement is realized by providing a plural group of rollers both on a stationary inking unit "and on a carriage inking unit of an offset proof press. Each roller group on the stationary inking unit and the carriage inking unit represents a particular color, respectively, and is operated to continue the kneading of the respective color ink. By the coopera tive control of these two inking units, a single proof press is advantageously used for testing a plurality of plates for multicolor printing.

The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objectives and advantages thereof, will be better understood from the following description considered in connection with the accorr ipanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example.

FIG. 1 schematically illustrates the inking arrangement in a conv ntional offset proof press.

FIG. 2 is to ili ustrate the elements of a preferred embodiment of th invention.

FIG. 3 shows ,safety stopper means for the carriage of the proof press; of the invention.

FIG. 4 is an electrical schematic representation of the stopper means of FIG. 3.

Before describing the details of the present invention, a typical inking arrangement in a conventional offset proof press will be briefly described with reference to FIG. 1. The machine of FIG. 1 is a flatbed offset proof press having a foot A for supporting a stationary member B. A carriage C is movably mounted on the stationary member or base B and has a blanket cylinder D and a damping unit E. Disposed on the base B are a form bed F and a printing bed G. At the right end in FIG. 1 of the base B, there is provided an inking arrangement which consists bf a pair of inking rollers H and an ink distributing roller I disposed between and slightly lower than the rollers I-I. These rollers H and I are driven to rotate continuously for kneading ink thereon. The carriage C has at ihe right end thereof in FIG. 1 a group of rollers comprising a pair of form rollers J, a vibrating roller K disposed between and slightly higher than the form rollers J, and an ink distributing roller L at a side of one of the form rollers J. The proof printing is conducted by the reciprocal movement of the carriage C on the base B.:Upon completion of one printing, the carriage C returns to its original position as shown in FIG. 1, where ink on the inking rollers H is transferred to the form rollers J. Then the carriage C is ready for being driven leftwards in FIG. 1 for next printing operation. The roller I and rollers K and L are so arranged to supply the ink uniformly onto the inking rollers H and the form rollers J, respectively. In such conventional inking arrangement, the rollers of the stationary and carriage inking units are joumaled to the base B and the carriage C, respectively. A proof press having such and inking arrangement makes it difficult to promote efficiency in proof press work, for the reasons mentioned above.

The invention will now be described with reference to FIG. 2, wherein discs 11 and 12 are rotatably mounted on the base 1 and the carriage 2 by means of shafts l2 and 22, respectively. The carriage 2 is driven to reciprocate on the base 1 for printing operation. It should be noted that the discs 11 and 21 are constructed in pairs, respectively, each pair of discs being coupled integral to each other by a connecting bar or the like (not sliown).

Along the periphery of the disc 11 in the base 1 are provided four groups of rollers, each group consisting of a pair of inking rollers 13a, 13b, 13c or 13d and an ink distributing roller 14a, 14b, 14c or 14d. Each pair of the inking rollers are so arranged that their peripheries slightly project beyond the peripheral edge of the disc 11 as shown.

Likewise, along the periphery of the disc 21 in the carriage 2 are provided four groups of rollers at regular intervals corresponding to the roller group intervals in the base 1. Each group of rollers in the carriage 2 consists of a pair of form rollers 23a, 23b, 23c or 23d, a vibrating roller 24a, 24b, 24c or 24d and an ink distributing roller 25a, 25b, 25c or 25d. Each pair of the form rollers are so arranged that their peripheries slightly project beyond the peripheral edge of the disc 21.

Thus, according to the invention the stationary inking unit and the carriage inking unit are provided with four groups of ink rollers correspondingly to each other. These ink rollers are so arranged that when the carriage 2 positions as shown in FIG. 2, the form rollers in one roller group in the carriage contact with the inking rollers in one roller group in the base so as to receive ink from the latter.

The base 1 and the carriage 2 have motors, transmission gears and clutches (not shown) for controlling the driving, stopping and free-rotation of the respective ink rollers in each roller group. There is provided a suitable mechanism for synchronizing the rotation of two discs 1 l and 21 in such a manner that the form rollers in the carriage match and contact with the inking rollers in the base at every 90 rotation of both discs and maintain the matching rotation during the time of taking-up of ink.

In operation, the carriage 2 is first shifted leftwards from the position of FIG. 2, then ink of the first color, for example yellow ink is supplied to the inking rollers 13a for kneading ink by the rotation of the rollers by a motor together with the ink distributing roller 14a. Then, the disc 11 is rotated 90 clockwise in FIG. 2 to move the second inking rollers 13b up to the top position, then ink of a second color or magenta ink is applied thereto, and then the rollers are rotated in the same manner as described above. Similar operations are repeated to apply a third color ink or cyan ink to the rollers 13c, and black ink to the rollers 13d.

Upon a full rotation of the disc 11, the first inking rollers 13a are placed again at the top position and the carrier 2 is moved to the right in FIG. 2 until the axis of the disc 21 is placed in the vertical plane which includes the axis of the disc 11. In this instance, the transmission is declutched to allow free rotation of the form rollers 23 as well as rollers 24 and 25. Thus, in the position of FIG. 2, the form rollers 23c will be urged toward and rotated with the inking rollers 13a, causing yellow ink to be transferred to the form rollers 230. After a suitable amount of yellow ink has been transferred to the rollers 23c, 240 and 25c, the carriage 2 is again moved to the left while turning the disc 11 90 clockwise and the disc 21 to counterclockwise with same angle, respectively. Then, the carriage 2 is returned to the position of FIG. 2 where magenta ink is transferred to the form rollers 23b from the second inking rollers 13 b. In the same manner, cyan ink is transferred to the form rollers 23a, and black ink to the form rollers 23d.

Thus the inking unit in the carriage 2 is ready for supplying ink of different four colors, yellow, magenta, cyan and black for effecting four-color printing process. Thus, by the rotation of discs 1 l and 21, it is possible to accomplish proof printing of a desired color.

During the proof printing by one color, the other three groups of form rollers in the carriage 2 continue, to rotate independently the respective color ink so that the carriage will be ready for starting the proof printing with a new color ink immediately after the change in position of the ,roller groups of the disc 21 in the carriage 2, resulting in saving the loss of time and promoting efficiency in proof press work. I

The flatbed offset proof press embodying the invention must be provided with means for matching a roller group in the carriage with a corresponding roller group in the base for selecting and receiving a predetermined color ink. Should the roller group be contacted with the roller group of different color, an undesired color mixture will be caused. FIGS. 3 and 4 illustrate such means for preventing such a color mixture by mistake.

As shown in FIG. 3, a normally closed microswitch 31 is provided at a side of the base 1. Provided at a side of the carriage 2 is a shoe member 41 for operating the contact member of the microswitch 31. The switch 31 and the shoe are so arranged that when the carriage 2 moves toward the inking arrangement of the base 1, the contacts in the microswitch 31 are opened by the shoe member 41 just prior to the time the carriage reaches the position tolmake contact with the base inking arrangement.

FIG. 4 showsan example of electrical circuitry of the means for stopping the carriage for prevention of color mixture, where; as will be seen, switches 32, 33, 34 and 35 are provided, each for the corresponding one of the inking rollers in the base 1 and arranged such that only the switch for the inking rollers taking the top position in the disc 11 will be closed upon each 90 rotation of the disc. There are also provided switches 42, 43, 44 and 45, each ftir the corresponding one of the ink rollers in the carriage 2, such that only the switch for the ink roller taking the bottom position in the disc 21 will be closed upon each 90 rotation of the disc 21.

The switches 32 to 35 and 42 to 45 are so arranged with reference to the discs 1 l and 21 that when the ink rollers of samecolor ink have come to contact to each other, the corresponding switch is closed.

Each switch in the base 1 is connected in series with the corresponding switch in the carriage 2, and four pairs of these switches are connected in parallel to each other and arranged in series relation with the circuit of the coil of a relay 51. The normally opened contact of the relay 51 is connected in parallel to the microswitch 31 for connecting with the circuit of a motor 52 which drives the carriage 2 for the reciprocating movement of the carriage.

Thus, when the carrier 2 is moved to the right to approach the ink rollers in the base 1, if one ink roller group in the base is contacted in opposed relation with a corresponding inkrroller group of same color in the stopped by a limit switch (not shown) upon arriving at that position.

However, if the roller groups which are contacted in vertically opposed relation, carry ink of different colors from each other, said corresponding switches connected in series are opened, so that the relay 51 will not be energized, and therefore when the contact of the microswitch 31 is opened by the shoe 41 of the carrier 2, the carrier stays at the position of FIG. 2, thereby precluding mixture of inks of different color.

Thus, according to the invention, it is possible to markedly reduce time and labor required for ink exchange in a proof press for multicolor offset printing, thereby enhancing the work efficiency. Also, any possibility causing color mixture by mistake of operation can be eliminated.

While the foregoing description has been devoted to the case of four-color printing, it will be understood that the present invention can also be applied to twocolor, three-color, five-color or more than 5 multicolor printing operations. It is also possible to use various other types of switches, such as photoelectrical switches, instead of the microswitch 31, and the mounting position of such switch may be varied suitably. For example, a photoelectric switch could be mounted on the base 1 in lieu of microswitch 31 so that when the carriage 2 moves toward the inking arrangement of the base 1, the contacts of the photoelectic switch are opened just prior to the time the carriage reaches the position to make contact with the base inking arrangement.

What is claimed is:

1. An inking arrangement in an offset proof press for multicolor printing comprising a press base frame, said base including means for mounting a printing plate and for mounting a substrate to be printed, a carriage, means for mounting said carriage for reciprocating movement on said base, said carriage including a rotatably mounted blanket roller, first plural inking units comprising groups of rollers arranged in a circle about a horizontal axis rotatably mounted on said base, means for supplying a different predetermined ink color to each inking unit in said base body, second plural inking units comprising groups of rollers arranged in a circle about a horizontal axis rotatably mounted on said carriage, each inking unit in said carriage representing a predetermined color to match and contact with a respective inking unit of the same predetermined color in said first plural inking units, means for selectively moving each inking unit of said first plural units into a position for engagement with a respective inking unit of said second plural units, means for selectively moving each inking unit of said second plural units into a position for engagement with a respective inking unit of said first plural units, means for moving said carriage from a position wherein a selected ink unit on said carriage engages a respective ink unit on said base through a position wherein said carriage ink unit contacts said printing plate, said means for moving also providing the function of transferring the inked image from said plate to said blanket roll for subsequent transfer to a substrate to be printed.

2. The inking arrangement as claimed in claim 1, in which said firstplural inking units and said second plural inking units are mounted on respective discs to allow said groups of rollers on said first and second plural inking units to be rotated about said horizontal axis.

3. The inking arrangement as claimed in claim 1, including means for automatically stopping the movement of said carriage after said selected ink unit on said carriage engages a respective ink unit on said base.

4. An inking arrangement as claimed in claim 3, in which each of the inking units in the base is provided with a first switch which is normally opened but is closed only when said inking unit takes its position to transmit its ink to the corresponding inking unit of the same predetermined color in the carriage, while each of the inking units in the carriage is provided with a second switch which is normally opened but is closed only when said carriage inking unit takes a position to receive a predetermined color ink from the corresponding inking unit of the base, said first and second switches being connected in series to each other and also connected to a carriage driving motor by means of a relay which is energized to allow said carriage to be driven to allow said inking units of the predetermined color to contact each other.

5. An inking arrangement as claimed in claim 4, in which the series-connected first and second switches are connected in series to a coil in said relay, and a normal open contact of said relay is connected in parallel to a third switch to be actuated with the movement of the carriage and said contact also being connected to the carriage driving motor.

6. An inking arrangement as claimed in claim 5, in which said third switch is mounted on the base of the press, and a shpe member is mounted on the carriage, said third switch being arranged to be actuated by said shoe member just prior to the time that the carriage inking unit reaches the position to contact the corresponding base inking unit.

7. The inking arrangement of claim 6, in which said third switch is a microswitch.

8. An inking arrangement as claimed in claim 6, in which said thirld switch is a photoelectric switch actuated by movement of the carriage. 

1. An inking arrangement in an offset proof press for multicolor printing comprising a press base frame, said base including means for mounting a printing plate and for mounting a substrate to be printed, a carriage, means for mounting said carriage for reciprocating movement on said base, said carriage including a rotatably mounted blanket roller, first plural inking units comprising groups of rollers arranged in a circle about a horizontal axis rotatably mounted on said base, means for supplying a different predetermined ink color to each inking unit in said base body, second plural inking units comprising groups of rollers arranged in a circle about a horizontal axis rotatably mounted on said carriage, each inking unit in said carriage representing a predetermined color to match and contact with a respective inking unit of the same predetermined color in said first plural inking units, means for selectively moving each inking unit of said first plural units into a position for engagement with a respective inking unit of said second plural units, means for selectively moving each inking unit of said second plural units into a position for engagement with a respective inking unit of said first plural units, means for moving said carriage from a position wherein a selected ink unit on said carriage engages a respective ink unit on said base through a position wherein said carriage ink unit contacts said printing plate, said means for moving also providing the function of transferring the inked image from said plate to said blanket roll for subsequent transfer to a substrate to be printed.
 2. The inking arrangement as claimed in claim 1, in which said first plural inking units and said second plural inking units are mounted on respective discs to allow said groups of rollers on said first and second plural inking units to be rotated about said horizontal axis.
 3. The inking arrangement as claimed in claim 1, including means for automatically stopping the movement of said carriage after said selected ink unit on said carriage engages a respective ink unit on said base.
 4. An inking arrangement as claimed in claim 3, in which each of the inking units in the base is provided with a first switch which is normally opened but is closed only when said inking unit takes its position to transmit its ink to the corresponding inking unit of the same predetermined color in the carriage, while each of the inking units in the carriage is provided with a second switch which is normally opened but is closed only when said carriage inking unit takes a position to receive a predetermined color ink from the corresponding inking unit of the base, said first and second switches being connected in series to each other and also connected to a carriage driving motor by means of a relay which is energized to allow said carriage to be driven to allow said inking units of the predeterminEd color to contact each other.
 5. An inking arrangement as claimed in claim 4, in which the series-connected first and second switches are connected in series to a coil in said relay, and a normal open contact of said relay is connected in parallel to a third switch to be actuated with the movement of the carriage and said contact also being connected to the carriage driving motor.
 6. An inking arrangement as claimed in claim 5, in which said third switch is mounted on the base of the press, and a shoe member is mounted on the carriage, said third switch being arranged to be actuated by said shoe member just prior to the time that the carriage inking unit reaches the position to contact the corresponding base inking unit.
 7. The inking arrangement of claim 6, in which said third switch is a microswitch.
 8. An inking arrangement as claimed in claim 6, in which said third switch is a photoelectric switch actuated by movement of the carriage. 